Network Data Model
CODASYL data model; DBTG data model
A database management system complies with the network data model when the data it manages are organized as data records connected through binary relationships. Data processing is based on navigational primitives according to which records are accessed and updated one at a time, as opposed to the set orientation of the relational query languages. Its most popular variant is the CODASYL DBTG data model that was first defined in the 1971 report from the CODASYL group, and that has been implemented into several major DBMSs. They were widely used in the seventies and eighties, but most of them are still active at the present time.
In 1962, C. Bachman of General Electric, New-York, started the development of a data management system according to which data records were interconnected via a network of relationships that could be navigated through . Called Integrated Data Store (IDS), this disk-based system...
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